Albeet b



(No Model.)

A. B. DICK. DUPLIGATING STENCIL.

PatentedTJ une 23 LANDREW EGRANAH, PND'TO-UTWEWAEHIN STEM-D C UNITEDSTATES I PATENT O FICE,

ALBERT B. DICK, OF. CHICAGO, ILLINOIS, ASSIGNCRTO THE A. B. DICKCOMPANY, OF SAME PLACE.

DUPLlCATlNG-STENCIL.

SPECIFICATION forming part of Letters Patent No. 562,590, dated June 23,1896.

Application filed December 27, 1887. Serial No. 259,171. (No model.)

- To all whom it may concern.-

Be it known that I, ALBERT B. DICK, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Means for ProducingDuplieating-Stencils and Printing Therefrom, of which the following is aspecification.

My object is to enable the production upon any ordinary type-writingmachine of a stenoil from which a large number of copies can be printed,which copies will accurately resemble ordinary type-written matter.

My object is further to provide simple and efficient means foraccomplishing this end; to produce a stencil from which a large numberof copies can be printed without permitting the ink to passtherethrough, except to form the letters of the typewritten matter; toprovide a protection for the stencil in printing, and generally to makethe apparatus convenient and efficient both in the preparation of thestencil and in the printing therefrom. I

In an application for patent already filed by me (Serial No. 252,003) isdescribed the process of preparing my duplicating-stencil. That processis based upon the principle that if a coated sheet of open material,such as thin porous paper, is covered on either or each side by a sheetof fine open-mesh fabric, such as silk bolting-cloth, the striking ofthe type of a type-writer upon the superim posed sheets will force thecoating of the paper into the meshes of the fabric and cause the coatingto adhere to the fabric upon the lines formed by the faces of the types,so

that when the sheets are separated the fabric sheet will carry away withit accurate representations of the type in the coating, and willleavethe fiber of the paper exposed and unprotected by the coating Whereverit has been struck by the type. The stencil which isthus formed willpermit the passage of ink through the openings or interstices betweenthe fibers of the paper where the same are left exposed, but willprevent the ink from passing through other parts of the sheet, and thus,by mounting the stencil in a frame, as will be well understood, andthoroughly ink- 111g one side of it with an inking-roller, du-

it can be put upon the sheet.

Japanese paper known as yoshino in J apan, or dental paper in the UnitedStates, is highly eificient, but other thin papers of equivalentopenness might be employed. This paper may be coated with paraffin inthe ordinary way of coating paper with paraffin for other purposes, butI have found that when this alone is done the coating is tenacious anddoes not readily break when struck by the type; but by adding to theparaffin a material which makes the coating friable this objection isovercome. For this purpose I have found that lard or lard-oil is anefficient material.

When I employ paraffin as the main ingredient of the coating, I mix theparaflin and lard or lard-oil preferably in the proportion of sevenparts of paraffin to one part of lard or lard-oil, whereby the paraffinis shortened. The paper is coated with this mixture after the manner ofthe usual paraffin process. The resulting coating is sufficientlytenacious to allow all ordinary handling of the paper, butis at the sametime so friable that the type in striking the surface will break intoand force the coating into the meshes of the silk bolting-cloth or othercovering or backing sheet on sharply-defined lines, so that in printingthe copies compare favorably in sharpness of the outline with theletters with original typeiwriting.

Another feature of the preferred construction of my stencil-plate is toprotect the coatin g on one side of the sheet by means of a thin coatingof elastic varnish. A great variety of elastic varnishes may beemployed, but I find that a mixture of gun-cotton and ether. forms agood varnish, and is preferable on account of its transparency and theease with which This protect- IOO z aozpvu ingvarnish is readily brokenby the type and does not detract from the easewith which the stencil isformed, and at the same time it protects the coating from the action ofthe ink and prevents the ink from passing through the sheets at anypoints where the wax coating may be defective or have become so by use.lVithout this coating of varnish it will sometimes be found that thecopies have inkspots upon them, which are produced by the ink passingthrough the wax coating where it is defective.

For preparing the stencil, I employ in 0011- nection with the waxedsheet a sheet of fine open-mesh fabric, such as silk bolting-cloth, andalso a sheet of moderately stiff oiled paper, the latter to furnish afirm backing for the fabric sheet. The fabric sheet and oiled backingare of the usual size of paper for type-writing machines, while thewaxed stencil-sheet may be made larger, although it is not necessarilyso. To place the sheets together for reception by the type-writer, Ifirst lay the stencil-sheet with its varnished face down, and then uponthe top of this I place the sheet of fabric and upon the fabric thesheet of oiled backing. The extending margins of the stencil-sheet arethen folded over the backing both at the sides and at the top and bottomand are smoothed down flat, so that they will stay in position. Thesuperimposed sheets are now arranged in a typewriter, as would be anordinary letter-sheet with the face of the stencil underneath, so as toreceive the impression from the type. The type-writer is thenmanipulated as usual, the

keys being struck with a firm even stroke, Before the type-writer isused, however, the inking-ribbon is removed and the type thoroughlycleaned, so that they will present sharp faces and will not be cloggedwith ink or other accumulations. After the entire matter to be copiedhas been impressed upon the stencil-sheet, the superimposed sheets areremoved from the type-writer, the margins of the stencil-sheet areunfolded, the oiled backing is first removed from the fabric sheet, andthen the fabric sheet is removed from the stencihsheet by lifting itcarefully from one corner.

The fabric sheet will carry away with it, adhering to its surface, therepresentation of the type-written matter in the wax coating which itremoves from the stencil-sheet, leaving the fiber of the stencil-sheetexposed and left unprotected by the wax-like coating on the lines whichhave been impressed by the type. The fibers of the paper of thestencilsheet are left exposed so that ink can pass between them. Thisstencil-sheet may be secured in a frame and its varnished side coveredwith ink by a roller, after which, by placing sheets of papersuccessively beneath the stencil, duplicates of the type-written mattercan be obtained by pressing the stencil with a roller upon the sheetbeneath. I prefer, however, to protect the face of the stencil-sheet byplacing overit a sheet of thin porous paper, such as that which formsthe body of the stencil-sheet, and secure the stencil-sheet and theprotecting-sheet in the printing-frame together. The inking-roller isthen run over the protecting-sheet until its pores are thoroughly filledwith ink as well as the exposed portions of the stencil-sheet beneath,when by additional rolling duplicates of the typewritten matter can beproduced. The protecting-sheet protects the face of the stencil frommechanical injury and has also an advantage in protecting the stencilfrom the action of the ink. Before securing the stencil-sheet andprotecting-sheet in the printingframe I cover the creases which weremade in the stencil-sheet by folding it over the oiled backing withstrips of waxed paper gummed on one side. These strips are pasted overthe creases before mentioned and prevent any ink from passing throughthe stencil on the line of the creases, which it would otherwise do,since the wax-like coating of the stencil is broken where the sheet iscreased. This necessity for covering the creases with strips of courseonly arises from the fact that the stencil-sheet is larger than theoiled backing and the fabric sheet. If all the sheets were of the samesize, there would be no necessity of creasing the stencil-sheet and thegummed strips before referred'to would not be required. Before using thefabric sheet again the adhering wax-like matter upon its surface isremoved by means of benzene or any other suitable solvent.

. In the accompanying drawings, forming a part hereof, Figure l is aplan View of the superimposed sheets ready to be placed in thetype-writer with the stencil-sheet broken away at one corner. Fig. 2 isa section through the superimposed sheets, the thickness of course beingexaggerated. Fig. 3 is a face view of the paper-stencil; Fig. 4, a topview of the printing-frame with the stencil and protecting sheetssecured therein, and Fig. 5 the vertical section through theprinting-frame.

A is the stencil-sheet, prepared with the wax-like coating and coveredwith varnish on one side, as already described. B is the sheet of fineopenfmesh fabric, such as silk bolting cloth. 0 is the backing of oiledpaper. These sheets are placed together, as shown in Figs. 1 and 2, andas previously described, and are then placed in a type-writing machineand the subject-matter to be copied is impressed upon them. They arethen removed from the type-writer and are separated, as alreadyexplained, when the stencil-sheet A becomes the stencil E. This stencil,after having the creases produced by folding covered with gummed stripsof waxed paper a, has its face covered with a porous protectingsheet F,and these two sheets are then secured at their edges in theprinting-frame G by means of the holding-frame b and suitable catches c.The protecting-sheet F is then filled with ink by an ink-roller, and byplacing a sheet of paper upon a suitable bed und er the printing-framethe stencil can be lowcred upon the bed and by passing the inking-rollerover the protecting-sheet ink will be forced through the stencil and thetypewritten matter will be impressed upon the sheet beneath. Theprinting-frame is then raised and other sheets placed beneath itsuccessively and the roller passed over the protecting-sheet, addingadditional ink from time to time, as required, until as many copies ofthe type-written matter are produced as are desired. 4

Although I have described herein the pro: cess of producing a stenciland desirable combinations of extractor-sheets with the stencilsheet, Ido not claim herein such processes or combinations, the same forming thesubj ect of my application, Serial No. 252,003, filed October 11, 1887.

What I claim is 1. A stencil-sheet or duplicating-stencil of openmaterial provided with a coating having a shortening material as aningredient, substantially as set forth.

2. A stencil-sheet or duplicating-stencil of open material provided witha coating of Wax mixed with a shortening material, substan-' tially asset forth.

3. A stencil-sheet or duplicating-stencil consisting of open materialcoated with a mixture of paraffin and lard-oil, substantially as setforth.

4. A stencil -'sheet or duplicating-stencil having a wax-like coatingand provided with an additional ink-proof elastic coating, substantially as set forth.

5. A stencil-sheet or duplicating-stencil consisting of open materialhaving awax-like coating and also coated with an elastic varnish,substantially as set forth.

6. The combination with a sheet of open material coated or impregnatedwith an inkproof substance such as paraffin, of a protective coveringfor such ink-proof substance composed of. asol ution of gun-cotton andether, substantially as set forth.

This specification signed and witnessed this 22d day of December, 1887.

ALBERT B. DICK. Witnesses:

ROBERT W. PARKER, Gus'r PETERSON.

